That night, in a room of the Blue Wallow Motel, circumstances offered Kyle Lansky the opportunity to avenge a haunting humiliation. He kills his brother's wife in cold blood and at last makes her pay for his contempt. But Lansky will enjoy his moment of triumph for only a short moment. Chance, so often capricious, has inserted a grain of sand in the machinery of his revenge. Unknown to the murderer, Clement Brown shared the room with the victim at the moment when she was assassinated. Convinced that the murder will be pinned on him because his is black, the unforeseen witness will trace back, step by step, the tracks on the route to Selma, which will lead him to the den of the real criminal.